Effect of a commercial air ionizer on dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae (Acari: Pyroglyphidae) in the laboratory

<p><b>OBJECTIVE</b>To investigate the short and long term efficacy of a commercial air ionizer in killing Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae) mites.</p><p><b>METHODS</b>The effect of a commercial ionizer on D. pteronyssinus and D. farinae was evaluated in the laboratory, using a specially designed test. Mortality was assessed after 6, 16 and 24 hours for direct exposure and after 24, 36, 48, 60 and 72 hours for exposure in simulated mattress. New batches of mites were used for each exposure time.</p><p><b>RESULTS</b>LT50 for direct exposure of ionizer was 10 hours for D. pteronyssinus and 18 hours for D. farinae. The LT50 for exposure in simulated mattress was 132 hours or 5.5 days for D. pteronyssinus and 72 hours or 3 days for D. farinae. LT95 for direct exposure of ionizer was 36 hours for D. pteronyssinus and D. farinae. Meanwhile, the LT95 for exposure in simulated mattress was 956 hours or 39.8 days for D. pteronyssinus and 403 hours or 16.8 days for D. farinae.</p><p><b>CONCLUSIONS</b>This study demonstrates the increasing mite mortalities with increasing exposure time of a commercial ionizer and suggests that negative ions produced by an ionizer kill dust mites and can be used to reduce natural mite populations on exposed surfaces such as floors, clothes, curtains, etc. However, there is reduced efficacy on mites inside stuffed materials as in mattresses and furniture.</p>

Practical Output Dosimetry with Undefined NdwCo-60 of Cylindrical Ionization Chamber for High Energy Photon Beams of Linear Accelerator / 의학물리

For the determination of absorbed dose to water from a linear accelerator photon beams, it needs a exposure calibration factor Nx or air kerma calibration factor Nk of air ionization chamber. We used the exposure calibration factor Nx to find the absorbed dose calibration factors of water in a reference source through the TG-21 and TRS-277 protocol. TG-21 used for determine the absorbed dose in accuracy, but it required complex calculations including the chamber dependent factors. The authors obtained the absorbed dose calibration factor NdwCo-60 for reduce the complex calculations with unknown Ndw only with Nx or Nk calibration factor in a TM31010 (S/N 1055, 1057) ionization chambers. The results showed the uncertainty of calculated Ndw of IC-15 which was known the Nx and Ndw is within -0.6% in TG-21, but 1.0% in TRS-277. and TM31010 was compared the Ndw of SSDL to that of PSDL as shown the 0.4%, -2.8% uncertainty, respectively. The authors experimented with good agreement the calculated Ndw is reliable for cross check the discrepancy of the calibration factor with unknown that of TM31010 and IC-15 chamber.

Non-pharmacological treatment for depression

In treatment of depression, non-pharmacological treatment is as important as pharmacological treatment. However, in clinical practice in Korea, non-pharmacological treatment is not provided sufficiently and patients are not satisfied with psychiatric interviews. Accordingly, patients ask for more information from clinicians. Clinicians should be aware of the characteristics of depression in Korean patients, because the manifestations of symptoms are influenced by cultural factors. In particular, depressed patients complain about somatic symptoms more frequently than they complain about depressed mood itself. In order to establish a therapeutic relationship with depressed patients, clinicians should be aware of these characteristics of depressed patients and clinicians should also address the needs of their patients. The author introduces evidence-based self-care methods for Korean patients with depression. St. John's wort, acupuncture, air ionization, light therapy, massage bibliotherapy, exercise, meditation, relaxation, and yoga can be helpful for overcoming depression. Among them, the Clinical Research Center for Depression, an organization supported by the Ministry of Health and Welfare, has recommended several non-pharmacological treatments for depression. First of all, exercise, such as walking more than 30 min. everyday, is strongly recommended. Other recommendations include bibliotherapy, interpersonal psychotherapy, cognitive behavioral therapy, and short-term psychodynamic supportive psychotherapy. For the nationwide management of depression, social bias against the treatment of depression should be reduced and non-pharmacological treatment for depression should be encouraged.

Evaluation of the Output Dose of a Linear Accelerator Photon Beams by Using the Ionization Chamber TM31010 Series through TG-51 Protocol to Postal Monitoring Output of RPC for 5 Years / 의학물리

This study is to keep the accuracy and stability of the output dose evaluations for linear accelerator photon beams by using the air ionization chambers (TM31010, 0.125 cc, PTW) through the Task Group 51 protocol. The absorbed dose to water calibration factor NdwCo-60 was delivered from the air kerma calibration factor Nk which was provided from manufacture through SSDL calibration for determination of output factor. The ionization chamber of TM31010 series was reviewed the calibration factor and other parameters for reduce the uncertainty within +/-2% discrepancy and we found the supplied NdwCo-60 which was derived from Nk has shown a -2.8% uncertainty compare to that of PSDL. The authors provided the program to perform the output dosimetry with TG-51 protocol as it is composed same screen of TG-51 worksheets. The evaluated dose by determination of output factor delivered to postal TLD block for comparison the output dose to that of MDACC (RPC) in postal monitoring program. The results have shown the 1.001+/-0.013 for 6 MV and 0.997+/-0.012 discrepancy for 15 MV X rays for 5 years followed. This study shows the evaluated outputs for linear accelerate photon beams are very close to that of international output monitor with small discrepancy of +/-1.3% with high reliability and showing the gradually stability after 2010.

Ultra-low luminescence of humid air and its possible role in negative air ion therapy.

One of the unresolved questions related to the mechanism of action of light negative air ions (reactive oxygen species) produced by air ionizers upon humans and animals is transmission of these short-living chemical species upon long distances from the place of their origin. We discovered the phenomenon which may probably resolve this problem. When a thin layer of water hydrating a hygroscopic surface absorbs rare UV-photons capable to split water molecules a flash of photon emission in UV- and visible regions of spectrum is observed. This flash (or oxygen-dependent oxidative processes underlying it) initiate reactions accompanied with generation of electronic excitation in the air contacting water film. Excitation propagates through the air at macroscopic distances, and the level of propagating excitation increases with elevation of air humidity. When air humidity exceeds 50% air excitation gains oscillatory-wave character. This phenomenon may endow into the mechanism of action of air ions generated artificially, and also into some natural processes where ordered water films may form and the latter may serve targets for energy impulses initiating oxygen-dependent oxidative processes in these films.

Câmara de ionizaçäo com ar comprimido e parede de alumínio para dosimetria em leventamento radiométrico / Pressurized air ionization chamber and aluminium walls for dosimetry in radiometric survey

Uma câmara de ionização de 23 cm3 com ar comprimido e parede de alumínio foi construída e apresenta sensibilidade uma ordem de grandeza maior quando comparada a câmaras de mesmo volume à pressão ambiente. A utilização de ar a uma pressão 2500 KPa minimiza sua dependência energética que se mantém menor que 5 por cento para energias de fótons na faixa de 40 KeV a 1.250 KeV. Esta câmara apresenta melhor desempenho do que as câmaras convencionais em medidas de baixas taxas de exposição.